Build Error - ResolveLibraryProjectImport task failed unexpectedly - access denied

Question

User239681 posted

Hello everyone,

Long story short, I believe something is wrong with either (or both) my Visual Studio and Xamarin install.

Basically, when attempting to build or run ANY project -- even have made new Blank App (android) projects with nothing in them -- I get this error while building.

1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: The "ResolveLibraryProjectImports" task failed unexpectedly. 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: System.ComponentModel.Win32Exception (0x80004005): Access is denied 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo) 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at System.Diagnostics.Process.Start() 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Xamarin.Android.Tasks.MandroidDaemon.CreateDaemon() 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Xamarin.Android.Tasks.MandroidDaemon.GetStandardInputLocked() 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Xamarin.Android.Tasks.MandroidDaemon.SendCommand(Task task, String[] commands, Action1 response) 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Xamarin.Android.Tasks.MandroidDaemon.ExtractResources(Task task, String importsDirectory, Boolean hashAssemblyDirectoryName, String outputDirectory, String outputImportDirectory, IEnumerable1 assemblies, String[]& jars, String[]& resolvedResourceDirectories, String[]& resolvedAssetDirectories, String[]& resolvedEnvironments) 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() 1>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1062,2): error MSB4018: at Microsoft.Build.BackEnd.TaskBuilder.d_26.MoveNext()

I have tried this with both 2013 and 2015. And I have also uninstalled/reinstalled VS and Xamarin.

Any advice would be appreciated. Thanks!

Answer 1

User239681 posted

When going to this specific file (called Xamarin.Android.Common.Targets) this is the section of code that appears to be set incorrectly. The pointers do not link properly. Anyone have any idea how to fix this?

"Target Name="ResolveLibraryProjectImports" Inputs="$(MSBuildProjectFullPath);@(ReferencePath);@(ReferenceDependencyPaths);$(AndroidBuildPropertiesCache)" Outputs="$(_AndroidLibraryProjectImportsCache)"> /Target"

Answer 2

User216094 posted

Same issue here, were you able to fix?

Error 2 The "ResolveLibraryProjectImports" task failed unexpectedly. System.ComponentModel.Win32Exception (0x80004005): Access is denied at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo) at System.Diagnostics.Process.Start() at Xamarin.Android.Tasks.MandroidDaemon.CreateDaemon() at Xamarin.Android.Tasks.MandroidDaemon.GetStandardInput_Locked() at Xamarin.Android.Tasks.MandroidDaemon.SendCommand(Task task, String[] commands, Action`1 response) at Xamarin.Android.Tasks.MandroidDaemon.ExtractResources(Task task, String importsDirectory, Boolean hashAssemblyDirectoryName, String outputDirectory, String outputImportDirectory, IEnumerable`1 assemblies, String[]& jars, String[]& resolvedResourceDirectories, String[]& resolvedAssetDirectories, String[]& resolvedEnvironments) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__20.MoveNext() App1

Some statements: - visual studio 2013 - android projects only are affected - xamarin studio on mac could build the same project without any errors - xamarin reinstallation didn't help

Answer 3

User240600 posted

Any update on this?

Answer 4

User240600 posted

I found this to be caused by security software running on my system. So check your anti-virus. I have seen threads on Avast! and in my case, I was running Cylance. Once I reconfigured Cylance, I was able to reinstall Xamarin and the issue went away. Hope this helps others avoid wasting time chasing this!

Answer 5

User243911 posted

Can someone provide more details on how to resolve this?

Answer 6

User78729 posted

It looks like there is something not installing. I've been having this issue for a while on the alpha channel. I've just downgraded Xam.Android to stable and can now compile. If I then change it back to alpha, it returns. Time to get it into BZ me thinks.

Answer 7

User211902 posted

Same problem here. I was using pre realease too and need change it back to stable version.

Answer 8

User83562 posted

Same problem here. Have only been using the latest stable version. Several attempts to repair and a complete reinstallation of VS2015 with Xamarin and Android SDK did not change anything. AV deactivation and/or running with Administrator privileges didn't work either. Installed Xamarin Studio... but exact same problem there.

The system: - Win7 Pro - VS2015 Pro with Update 3 - Xamarin 4.1.1.3 - Gtk# for .NET 2.12.38 - Xamarin Studio 6.0.2 - JDK 1.7.0.550 - Android SDK 1.16

Appreciate any more hints of how to fix this.

Answer 9

User83562 posted

After many more failed attempts today I tried to update Xamarin from latest stable to latest beta.... IT WORKS NOW! Currently running Xamarin 4.2.0.628... and not touching it as long as it keeps working... this fragile flower cost me 2 days :-/

Answer 10

User2029 posted

+1, the bug affect the current beta channel. Does anyone from Xamarin really read customer reports ?

Answer 11

User76808 posted

+1 same issue here, just upgrade xamarin studio and open up my project with xamarin studio and close it. Use visual studio to open the project and build to see this error.

Answer 12

User134020 posted

had the same error after updating xamarin to v7. just fixed with clean all - build all - deploy

Answer 13

User257894 posted

same issue here, but i must have caused it by clicking everything trying to learn this stuff. All I did to fix it was reinstall XamarinInstaller.exe - which was quick, as it only does a repair of sorts it seems.

Answer 14

User212566 posted

same here, Xamarin Studio 6.1 on windows, creating Forms app causes this error.

Answer 15

User65 posted

https://bugzilla.xamarin.com/show_bug.cgi?id=44460

Answer 16

User497 posted

+1 Same Issue Here

It only happens after some time, but when it occurs once, then it occurs with every attempt to compile. It can be solved by closing and re-starting Visual Studio. Yet, it is very annoying to regularily have to re-start Visual Studio in order to compile :-/

Answer 17

User497 posted

As a side note: Is it possible to completely disable or even uninstall the Xamarin Android Designer? I don't use it at all and I don't need it.

Answer 18

User2029 posted

AndreasSelle: rename .axml files to .xml Will compile and run fine. No more custom designer / buggy xml editor, only fast native xml vs editor.

Answer 19

User142812 posted

Having the same error message as described here. It happens after my designs (.axml) were opened in the Design Viewer. Rebuilding and cleaning solution don't work. Only solution is to restart VS.

Answer 20

User239596 posted

I am experiencing the same issue.

Answer 21

User45371 posted

Hi all, the only way I'm able to compile is if I close down all my .axml files and restart Visual Studio. I even tried opening the .axml file as xml with open with... It still opened in Android editor which is definitely the problem. I really liked the suggestions of renaming .axml to xml files (because I never use the Android UI editor anyway, just raw xml). This seems to work great.

So now I have quicker opening of my layout files and I can compile!

Be nice if Xamarin fixed this bug soon though. Hope this helps someone.

Answer 22

User261349 posted

I am experiencing the same issue. --;

Answer 23

User260196 posted

Hello everyone,

I tried to update Xamarin latest stable(4.2.0.703). It works.

Answer 24

User19502 posted

Workaround: Check your projects to see if there are any broken references. (marked with yellow triangle) Delete all broken references. Recompile.

For us, the bug is that VS improperly reports broken refs with this misleading error '"ResolveLibraryProjectImports" task failed unexpectedly'.

Answer 25

User251406 posted

any update on this? i have the same issue , updating or downgrade didn't work

Answer 26

User5953 posted

close multiple studios

Answer 27

User181338 posted

Restarting VS and other solutions above didn't work for me.

I had to unload both Android & iOS projects (in this case they're the only ones we're working on) and try and build. The error was coming from my Droid project so then I could see all the actual issues from my PCL (had just done a load of refactoring so lots of issues), once I had solved these I reloaded the Droid project and it built/deployed fine.

Hope this helps!

Answer 28

User120789 posted

Valuable tip @NinjaFocks ! Thanks.

Answer 29

User288902 posted

Worked for me to turn off Avast and rebuild the solution.

Answer 30

User277909 posted

In my case, I was getting error The "ResolveLibraryProjectImports" task failed unexpectedly. when I open a project downloaded from Xamarin.University on Windows 10 and the path for one of the files ends up being to long (longer than 260 characters). So, to solve my problem, I would copy the directory as shallow as possible, so instead working directly in the structure of downloaded project, I would copy deepest directory containing the project into my C:. Building would work then without an issue as the path to all files in the project got shortened.

Answer 31

User286075 posted

Ok, it's a little bit strange...In my case a cause of error seemed an corrupted .xaml file. Clean project, then exit of VS works, but after clean all and rebuild the whole application, one .xaml file seemed to continue with error. then i copied the code into another editor, deleted it and recreate it again, then i pasted the code back. seems to work with me.

Answer 32

User88553 posted

@dinobuljubasic said: In my case, I was getting error The "ResolveLibraryProjectImports" task failed unexpectedly. when I open a project downloaded from Xamarin.University on Windows 10 and the path for one of the files ends up being to long (longer than 260 characters). So, to solve my problem, I would copy the directory as shallow as possible, so instead working directly in the structure of downloaded project, I would copy deepest directory containing the project into my C:. Building would work then without an issue as the path to all files in the project got shortened.

I have the same problem with a project I downloaded from Github. Just like you @dinobuljubasic, I moved the deepest project up the folders and reload it into VS. It built without any more errors. :)

VS should have detected the problem and provided a clearer error.

Answer 33

User127089 posted

@Halukmy said: close multiple studios

Thanks Halukmy - this worked for me. I had a sample project open next to my main XF project and sample refused to build. As soon as I closed my main XF project the sample built OK.

SteveG

Answer 34

User194178 posted

For my case it was long TFS path, after shortening it all is fine.

Answer 35

User239535 posted

My problem with this message was related to resulting path depth over 260. Moved the project to c:\ and compiled OK !

Answer 36

User294638 posted

remove bin/obj directories , worked for me

Answer 37

User309346 posted

ResolveLibraryProjectImport task failed unexpectedly

Answer 38

User309346 posted

plz help

Answer 39

User246263 posted

I am having the same issue "The "ResolveLibraryProjectImports" task failed unexpectedly." in Xamarin. Android. Deleting bin ,obj file did resolve the issue. Also tried restarting the VS and PC too.

Please help. :|

Answer 40

User305828 posted

I had the same problem, I updated Xamarin.forms and android SDK and It resolved part of the problem. It seemed that there was a problem with Hyper-V and VS Android Emulator (Because both of them use the same hd resourses) , so I turned it ( Hyper-V ) off, and the problem was resolved.

Answer 41

User313471 posted

I'm having same issue here... any help will be appreciated

Answer 42

User253201 posted

Help needed, Error The "ResolveLibraryProjectImports" task failed unexpectedly.

Answer 43

User314294 posted

Same here.

The "ResolveLibraryProjectImports" task failed unexpectedly. System.IO.FileNotFoundException: Could not load assembly 'My.Xam, Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile? File name: 'My.Xam.dll' at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.GetAssembly(String fileName) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(DirectoryAssemblyResolver res, ICollection1 jars, ICollection1 resolvedResourceDirectories, ICollection1 resolvedAssetDirectories, ICollection1 resolvedEnvironments) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext()

Answer 44

User246263 posted

When I get this I had cleaned the project . Deleted the bin,obj files and rebuild the solution. Also changed the long path of the project. Worked for me.

Answer 45

User316549 posted

I had the same problem earlier with sample project. I updated the xamarin.forms for every project to the stable version instead of uninstalling the older one and installing back. Clean the solution and rebuild, the problem resolved without any error.

Answer 46

User234656 posted

I had this same error with project working fine on other computer. Turned out file+pathnames became too long (> 260 characters).

Moved working directory closer to root, that fixed everything.

Answer 47

User252595 posted

Go to the project file and delete everything inside bin and obj folder. Works for me.

Answer 48

User317643 posted

Run visual studio as administrator worked for me... Press windows button from keyboard and type visual studio .. Then right click on visual studio and select "Run as administrator"..

Answer 49

User235668 posted

I was able to see the missing components after uninstalling Xamarin.Forms and re-installing.

Answer 50

User317950 posted

Still having this error pop up on my projects. Have tried all the usual solutions that have been posted on here with no success.

Answer 51

User304338 posted

I had the same error, by mistake i typed SS in Margin="0,10,10SS,0" property. After removing SS, project executed successfully. You may have some mistakes in your projects like i did.

Answer 52

User326813 posted

I had same problem! What worked for me I just checkout my project to different and shorter folder path(C:/VSProjects/) as @Prajakta.Shinde mentioned in her post.

@Prajakta.Shinde said:

When I get this I had cleaned the project . Deleted the bin,obj files and rebuild the solution. Also changed the long path of the project.

I have current setup: Visual studio 2015 Xamarin v4.5.0.476

Answer 53

User176361 posted

• Close the project.
• Delete the folders bin and obj from solution.
• Reopen the project.
• Clean and Rebuild the project.

I hope I have helped.

Answer 54

User292169 posted

I know this doesn't apply to everyone who has posted, but it is what brought me to the thread in the first place.

    <ListView.GroupHeaderTemplate>
        <DataTemplate>
            <TextCell Text="{Binding Name}"
                Detail="{Binding Keyword}"
                TextColor="#f35e20"
                DetailColor="#503026" />
            <Button Text="Edit"/>
        </DataTemplate>
    </ListView.GroupHeaderTemplate>
</ListView>

Answer 55

User11701 posted

I was creating a brand new Xamarin.Forms app using Visual Studio 2017 and hit this error.

I had updated all my nuget packages and was rebuilding when it happened - this is a skeleton application at this point so I had no idea what was happening. Was is an incompatible Nuget package or did one of them not install correctly?

No, not a Nuget problem at all as it happens.

The problem was that I had let Visual Studio save it to its default location and somewhere along the lines there is a files whose complete path is too long!

Yep - I kid you not. In this day and age 'Path Too Long' is still a problem on Windows!

Moved to root of my D drive and all is well now!

Answer 56

User277209 posted

Got this same issue but not at all able to del the bin/obj, specifically ...Droid\obj\Release_libraryprojects_\MPAndroidChart**libraryproject_imports**

Answer 57

User169571 posted

In my case i accidentally referenced a Windows only library in the pcl. The error message showed it but took me some time to notice. After removing it the project was building again.

Error The "ResolveLibraryProjectImports" task failed unexpectedly. System.IO.FileNotFoundException: Could not load assembly 'Windows.Foundation.UniversalApiContract.winmd, Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile? File name: 'Windows.Foundation.UniversalApiContract.winmd.dll' at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.GetAssembly(String fileName) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(DirectoryAssemblyResolver res, ICollection1 jars, ICollection1 resolvedResourceDirectories, ICollection1 resolvedAssetDirectories, ICollection1 resolvedEnvironments) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()

Answer 58

User217567 posted

I had the same problem. Check your path where you started your application. Mine was in C:\Users\Gary\Documents\Visual Studio 2017\ and the path was too long. Stinking Windows. I put it into C:\Source and the problem went away.

Answer 59

User253623 posted

I tried many solutions with deleting bin & obj folder, clean, rebuild, changing build configurations etc.but the only reliable workaround for me is to close and reopen Visual Studio for WIndow,but Still the Problem no Solve..

Answer 60

User24062 posted

Yup, here we are in the 21st century still stuck with a DOS criteria from the 1980s. Hit this again today after installing a Nuget package and browsing through the package it didn't seem add anything that should have thrown the error so possibly a VS bug.

Answer 61

User212025 posted

I encountered this error today and it appears to be related to the path for the project being too long. Moving it to a more shallow path should solve this exception.

Answer 62

User28549 posted

Another way this will manifest itself is if you put a collection of views inside a container that does not accept children.

xml <!-- this will break --> <ContentView> <ContentView.Content> <!-- this needs to be wrapped in a view that accepts children like <Grid />, <StackLayout />, etc --> <Label Text="Foo" /> <Button Text="Foo" /> </ContentView.Content> <ContentView>

Answer 63

User353052 posted

I had the same problem and after inspecting the error message it was saying that the path to some source files were too long. After changing some directory names to short the overall path, everything worked

Answer 64

User14370 posted

@Halukmy said: close multiple studios

Thanks that solved my problem

Answer 65

User250011 posted

Had same problem. Here is my solution

1. Restart Visual Studion
2. Open the Project
3. Clean the solution
4. Rebuild the solution
5. Close solution
6. Reopen the project

Answer 66

User354499 posted

Par for the course with frameworks like this in VS. Build and build often is the lesson here! This is almost a trickle-down problem and can be very difficult to find the REAL reason. Here was mine...

See the real issue above was: "Specified argument was out of the range of valid values." Very difficult to see / figure out where that error is coming from as well. It was bad binding attempt to "Desc" property. Normally an invalid binding just silently fails and I still have no idea why this one caused a bad build. Had to rollback to figure it out.

If I tried cleaning / rebuilding, the subsiquent ResolveLibraryProjectImport task failed error would occur and obfuscate the real issue.

Answer 67

User358596 posted

I had the same issue, i moved the code to an upper directory which resolved the issue for me

Answer 68

User128730 posted

I have the same issue here , using Visual Studio 2017 for xamarin forms. Does anyone found solution ?

Answer 69

User332304 posted

Downloaded the appropriate Nuget packages. Cleaned the project. Unloaded the project. Reloaded the project. Restarted Visual studio. Again Unloaded the project. Reloaded the project. Then it worked.

Not sure whether this will work for everyone. But always try to do these things before jumping on to more complicated solutions. This is pretty much XAMARIN 101.

Answer 70

User354662 posted

Just Change the location of your project to shortest path, that's it error will disappear

Answer 71

User360954 posted

I am getting following error.

Severity Code Description Project File Line Suppression State Error The "ResolveLibraryProjectImports" task failed unexpectedly. System.IO.FileNotFoundException: Could not load assembly 'KtMobileApp, Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile? File name: 'KtMobileApp.dll' at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(DirectoryAssemblyResolver res, ICollection1 jars, ICollection1 resolvedResourceDirectories, ICollection1 resolvedAssetDirectories, ICollection1 resolvedEnvironments) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext() KtMobileApp.Android

Answer 72

User324119 posted

I do not understand why all the time there are some strange problems. Constantly, some connections are lost or some problems with import! It is impossible to work because of unstable work of xamarin :s :s :s :s :s :s :s :s :s :s :s

The "ResolveLibraryProjectImports" task failed unexpectedly. System.IO.FileNotFoundException: Could not load assembly 'AQTMobile, Version=0.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile? File name: 'AQTMobile.dll' at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve(String fullName) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Extract(DirectoryAssemblyResolver res, ICollection1 jars, ICollection1 resolvedResourceDirectories, ICollection1 resolvedAssetDirectories, ICollection1 resolvedEnvironments) at Xamarin.Android.Tasks.ResolveLibraryProjectImports.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext()

Answer 73

User368218 posted

I'm getting this error as well (ResolveLibraryProjectImports) and I think this error is just hiding other errors. I went through my build log (set to Detailed in VS options) and I found some other errors occurring and when I resolved THOSE errors, this error went away. So, I think this error might be the result of some buggy tooling not exposing the underlying errors. I'm just guessing, though.

Answer 74

User21269 posted

I was able to figure this out: See link "bugzilla.xamarin.com/show_bug.cgi?id=41968#c2"

Basically, I wanted to use "ApplicationData.Current.LocalFolder.Path" from my .NET Standard library project(to use from my UWP project, using "Device.RuntimePlatform" enum) so it added a reference to "Windows.Foundation.UniversalApiContract.winmd.dll". I changed the folder to "Environment.SpecialFolder.LocalApplicationData" for my UWP project and I removed the ref to "Windows.Foundation.UniversalApiContract.winmd.dll". Voilà!. Problem Solved!

I HTH G.P.

Answer 75

User236424 posted

@dinob said: In my case, I was getting error The "ResolveLibraryProjectImports" task failed unexpectedly. when I open a project downloaded from Xamarin.University on Windows 10 and the path for one of the files ends up being to long (longer than 260 characters). So, to solve my problem, I would copy the directory as shallow as possible, so instead working directly in the structure of downloaded project, I would copy deepest directory containing the project into my C:. Building would work then without an issue as the path to all files in the project got shortened.

This worked for me!

Answer 76

User373674 posted

I manually deleted bin/obj folders, cleaned, rebuilt, restarted etc. but it didn't help. File path lengths were not an issue either. I ended up re-installing Xamarin.Forms and that seems to have fixed this problem...for some reason.

Answer 77

User115860 posted

In my case, there was no way to fix it by cleaning, rebuilding, deleting bin and obj folders or restarting VS. The error message was very weird. Together with the error of this topic I had a "Value cannot be null. Parameter name: method". Which was pointing to line 1 of a XAML file. Totally no sense. Then I started to remove part of the XAML code in that file, and I found it was building. With this "monkey approach", I've been removing XAML code, building and see if it worked or not. Finally I found there was an error on a Label item. The FontSize attribute was not correct. Fixed it, and it finally worked. But this is frustrating. Lost hours to find it. The build process from the nineties, purely from command line, was more precise in giving you the error position.